Finding optimum solution

Enzyme catalysis:
Specificity is about binding. When we say that an enzyme is exclusively specific to a particular substrate it only binds with that substrate and in a sense repel other substances. For being strictly specific correct form of binding must be strictly necessary for catalysis.
This specificity will also result in strong binding. There is a problem with strong binding because if so after the reaction or chemical transformation, product will not easily leave the enzyme and make it available for new substrate. This will slow the actual rate of transformation of substrates. So good enzymes should give only marginal time for reaction to occur and release the product. This is about enzyme affinity for substrate which is directly related to binding. Strong binding (high specificity) will oppose quick release.
Rate of transformation inside the enzyme is also a function of binding. Releasing is also a function of binding. If they were separate event one would say that for a good enzyme, the binding affinity for substrate (of an enzyme) will be such that to match the average time of transformation.
But the reality is that rate and binding affinity is not independent from each other so that they can move freely to be adjusted to an optimum. They are connected - changing binding affinity inconsiderately can effect rate. Rate is not only dependent on substrate binding but also with the binding with transitional state, so there may be ways in which we can change binding affinity still not changing the rate.